Gentlemen,

2000 XP, EB, 5.4l, 100k-miles, recent coils and tranny, had it a month.

Yesterday, after sitting for three days in 5F and below weather, I started it up. For the first time, had an engine knock. It went away as it warmed up until it was completely gone.

When I bought it, the oil level was down just below the "fill" line, even though the oil pressure guage showed full oil pressure when running. S the first thing I did was add about 3 litres of oil. Treated it to the expensive synthetic stuff. Then did ~500 miles of highway driving.

Should I be concerned about the cold-start knock?

 

I've had that cold winter knock and so have many other members. And I was worried at first, but I've had the truck almost 4 years now, and it still knocks for about 3 minutes or so, and basically goes away (I hear slight knocks, could be from gas, etc) plus i have over 155k miles on her. As long as you checked the oil and it looks good, I wouldn't worry, just check periodically.

 

I was just in Utah for a few days at 8-9 below zero and it was an amazing knocking sound on startup. But as many have mentioned....it goes away.

However, it knocked less when I added half a quart of oil to bring it up to full.

 

Did some research.

From http://www.carcomplaints.com/Ford/Ex...998/tsbs.shtml

Technical Service Bulletins for 1998 Ford Expedition

TSB #13322 -- SOME VEHICLES MAY EXHIBIT AN ENGINE KNOCK AT INITIAL COLD STARTUP. *TT (NHTSA ID #609613, OCTOBER 01 1999)
TSB #13331 -- SOME VEHICLES EQUIPPED WITH ENGINES PRODUCED BY WINDSOR ENGINE PLANT MAY EXHIBIT AN ENGINE KNOCK AT INITIAL COLD STARTUP. *TT (NHTSA ID #6092152, OCTOBER 01 1999)

Seems they didn't get it fixed.

 

Just curious if any of you guys that have cold start knock have the block heater and have you tried using it when it's cold?

In general it doesn't get cold enough where I live to experience the knock, but my expy has a block heater, so I'm wondering if that makes a difference.

 

I do have the block heater, but here on Long Island its rare that the temps drop below 10 degrees for any length of time, and I haven't tried using it yet.

 

I think a block heater will keep your engine warm enough that it wont knock. i wish I had one, but keeping it in the garage seems to keep it warm enough that it doesnt knock. If I am outside overnight, then it might knock for a bout 5 seconds. I use Mobil 1 high mileage 5w30 oil and keep tabs on the dipstick once per month. 170k on mine right now.

 

My 99 Expy (100K) has the same light knocking sound on initial startup. Doesn't make much difference if it's cold or warm outside. It knocks a little, almost sounds like a quiet diesel, and then decreases until it simply stops 45-60 seconds after start. It's done this for several years and no symptoms or trouble in any way.

Last week I added Seafoam to the crankcase and fuel. I also added it into the intake manifold through the brake booster vacuum line, let it sit for about 30 mins and then restarted and clouded up the entire neighborhood. I considered this a full cleaning as it treated the injectors, the crankcase and the intake. Bottom line is after I replaced the oil, I noticed several improvements in power and smoothness including (I'll be danged) the knock almost went away. I can still hear it but it's something that you would only notice if you're paying attention. The Seafoam must have cleaned something that was causing the knock because it is much improved.

I'm pretty certain there is something in the design that causes the lifters to be a little noisy until they are fully lubricated. If you think Expys are bad, listen to some Suburbans and Yukons. Now that's noisy.

 

My Expy makes the same knocking sound when I start it in the morning. So does my Dad's 2000 E-250. I think there is a thread in the 5.4/4.6 Modular forum explaining this mysterious knock. It has something to do with the piston skirts being designed rather short and thus flapping around inside the cylinder until normal operating temps have been reached.
Some have had luck on fixing this sound by switching to original Motorcraft FL-820S oil filters, so that is certainly something to try. Although I do use the above mentioned filter and still expereince some knocking.
Jones: I agree with you on those Yukons and Suburbans sounding bad. My neighbor has one and it makes all kinds of racket when he starts it in the morning. My Expy is a 98 and his Yukon is an 03 and mine doesn't sound nearly as bad.

 

That makes sense that the oil filter could cause some of the problem. Maybe the Fram and Bosch filters that I use are too restrictive and delay the oil getting to the right parts.

Whatever it is, it seems to get better with a thorough intake, injector and crankcase cleaning.

 

My 97 F150 had some lifter noise but i haven't heard a thing for about 7 months now. I agree with how noisy Suburbans and Yukons are. Our family owns a 99 Suburban and some times you can really here that thing make a racket. It only has 119xxx on it, and my 97 F150 4.6 has 196xxx and knocks but you hardly notice it.

Same thing with my 97 F150 4.6 w/ 196xxx on it. I have a slight knock when it's cold but goes away once warmed up. I am using MC 5w30 oil and the FL-820S filter.